Gene and polypeptide relating to breast cancer

Abstract

The present application provides novel human gene B7330N whose expression is markedly elevated in breast cancers. The gene and polypeptide encoded by the gene can be used, for example, in the diagnosis of breast cancers, as target molecules for developing drugs against the disease, and for attenuating cell growth of breast cancer.

The invention claimed is: 
     
       1. A method of screening for a compound for treating breast cancer, said method comprising the steps of:
 (a) contacting a test compound with a polypeptide selected from the group consisting of: 
 (1) a polypeptide comprising the amino acid sequence of SEQ ID NO: 27; 
 (2) a polypeptide encoded by the nucleotide sequence of SEQ ID NO: 26 which is expressed endogenously or exogenously by cells; 
 (b) detecting a biological activity of the polypeptide of step (a), wherein the biological activity is acetylgalactosaminyltransferase; and 
 (c) identifying a compound that suppresses the biological activity of the polypeptide in comparison with the biological activity detected in the absence of the test compound; 
 (d) culturing animal cells which express the polypeptide defined in (a) (1) in the presence of the test compound identified in step (c); 
 (e) detecting the promotion of proliferation of the animal cells; and 
 (f) identifying a compound that suppresses the promotion of proliferation of the animal cells in comparison with that detected in the absence of the test compound, as a candidate compound to be used for the treatment of breast cancer. 
 
     
     
       2. The method of  claim 1 , wherein the proliferation of the animal cells is detected by measuring colony forming activity.